Measurement of the neutron capture cross-sections of Dy and Hf in the energy region from 0.003 eV to 50 keV

The capture cross-sections of Dy and Hf were measured in the energy region from 0.003 eV to 50 keV by using the neutron time-of-flight method at the 46 MeV electron linear accelerator of the Research Reactor Institute, Kyoto University. An assembly of Bi4Ge3O12 (BGO) scintillators, which was placed at a distance of 12.7+/-0.02 m from the neutron source, was employed as a total absorption detector for the prompt capture gamma-ray measurement on the sample. In order to determine the neutron flux impinging on a capture sample, we used the Sm(n, gamma) reaction for thermal neutrons and the B-10(n, alpha gamma) reaction for neutrons from 0.003 eV to 50 keV. The absolute capture yield for the sample was obtained from the saturated resonance data at a large resonance of the sample. For the capture cross-section of Dy, the existing experimental data and the evaluated data in ENDF/B-VI and JEF-2.2 are close to the present result. For the Hf capture cross-section: the previous experimental data. and the evaluated data in JENDL-3.2 and ENDF/B-VI are in general agreement with the present measurement.